1. Field of the Invention
The present invention is related to a refrigerator, which is capable of changing functions of its compartments at user's wish, and a control method therefor.
2. Description of the Prior Art
A conventional refrigeration cycle consists of a series of refrigerant phase changing means which are embodied by a compressor, a condenser, an expansion valve (or a capillary tube) and an evaporator, and a refrigerant tube for connecting the phase changing means in series with each other.
On the other hand, a so-called direct cooling type refrigerator generally has two evaporators arranged in its freezing and refrigerating compartments, respectively, and a three-way valve whose inlet and one of the two outlets are inter-connected with respective ones of the evaporators. In the direct cooling type refrigerator, the flow of the refrigerant into each evaporator is controlled by the three-way valve. More specifically, the inlet of the three-way valve is connected to the outlet of the evaporator for the freezing compartment, and one outlet of the three-way valve is connected to the inlet of the evaporator for the refrigerating compartment. The other outlet of the three-way valve is directly connected through a bypass tube to the inlet of a compressor. In the configuration, the refrigerant which passes through the evaporator for the freezing compartment either flows to the evaporator for the refrigerating compartment or is directed to the compressor according to the position of a spool, in the three-way valve, thereby maintaining the desired temperatures in the freezing and refrigerating compartments.
However, there is an inconvenience in the conventional direct cooling type refrigerator in that the user can not optionally alter the functions for the compartments according to the amount of food to be stored because the functions for the compartments are fixed to the freezing and refrigerating compartments.
Recently, there has been developed a refrigerator having a compartment which can either ferment or refrigerate a fermentation food such as Kimchi therein. Kimchi is a Korean traditional food which is made of radish, cabbage or cucumber, and spiced with pepper, garlic, onion, ginger, etc. An example of this type of refrigerator is disclosed in commonly owned U.S Pat. No. 5,228, 499. However, the U.S Patent is related to a so-called indirect cooling type refrigerator. The indirect cooling type refrigerator controls the amount of cool air which is generated from a single evaporator and then supplied to each compartment by the opening or closing of dampers arranged in the compartments.
However, a direct cooling type refrigerator having a compartment in which the food can be either fermented or refrigerated has not been developed. It is well known that the direct cooling type refrigerator has an advantage in that the temperature of any given compartment can be quickly raised to a desired temperature. Because the technique for fermenting Kimchi is disclosed in U.S Pat. No. 5,142,969, a more detailed description therefor will be omitted from this specification.